The statements in this section merely provide background information related to the present disclosure and may or may not constitute prior art.
Automatic transmissions typically include a hydraulic circuit or system that uses a hydraulic fluid, such as oil, for various purposes throughout the transmission. For example, the hydraulic system directs oil to various transmission components to act as lubrication between moving components, to act as a cooling system for dissipating waste heat, and to act as a hydraulic control system for actuating various devices. One typical device that is hydraulically actuated in an automatic transmission is a torque transmitting apparatus such as a clutch or brake. Torque transmitting devices work in combination with other torque transmitting devices and with various gear sets to provide a plurality of forward and reverse gear ratios between an input shaft and an output shaft.
In many applications it is preferable that the input shaft and the output shaft be concentric to one another and share the same axis. Additionally, in order to hydraulically actuate, lubricate, or cool the various components of the transmission, including any torque transmitting devices directly connected to the output shaft, it is preferable that fluid be directed through the input shaft to the output shaft. However, because the input and output shafts must rotate at different speeds, it can be difficult to transfer fluid between the shafts. One solution has been to radially align both the input shaft and the output shaft with a fluid feed port. However, this requires that the output shaft be located within the input shaft and therefore have a smaller outer diameter due to stacking issues with seals and hydraulic fluid galleries. Accordingly, there is room in the art for an assembly with a hydraulic feed system that allows the shafts to have near identical diameters, allows for ninety degree gallery turns, and eliminates the need for seal stacking.